diff --git a/client/fieldedit.cpp b/client/fieldedit.cpp
index 909a0b6..3d956d1 100644
--- a/client/fieldedit.cpp
+++ b/client/fieldedit.cpp
@@ -55,3 +55,19 @@ void FieldEdit::setRange(quint64 min, quint64 max)
 {
     uint64Validator_.setRange(min, max);
 }
+
+QString FieldEdit::text() const
+{
+    QString str = QLineEdit::text();
+
+    switch (type_) {
+        case kMacAddress:
+            str.remove(QRegularExpression("[:-]"));
+            str.prepend("0x");
+            break;
+        default:
+            break;
+    }
+
+    return str;
+}
diff --git a/client/fieldedit.h b/client/fieldedit.h
index 56eb8f4..f3efe05 100644
--- a/client/fieldedit.h
+++ b/client/fieldedit.h
@@ -42,6 +42,8 @@ public:
     void setType(FieldType type);
     void setRange(quint64 min, quint64 max);
 
+    QString text() const;
+
 private:
     FieldType type_{kUInt64};
 
diff --git a/client/findreplace.cpp b/client/findreplace.cpp
index 9d580a9..c96c65f 100644
--- a/client/findreplace.cpp
+++ b/client/findreplace.cpp
@@ -92,14 +92,21 @@ void FindReplaceDialog::on_field_currentIndexChanged(int index)
 
     FieldAttrib fieldAttrib = fieldAttrib_.at(index);
 
-    qDebug("XXXXXX %s bitSize %d max %llx", qPrintable(field->currentText()),
-            fieldAttrib.bitSize, fieldAttrib.max);
+    // Use heuristics to determine field type
+    if (fieldAttrib.bitSize == 48) {
+        findValue->setType(FieldEdit::kMacAddress);
+        replaceValue->setType(FieldEdit::kMacAddress);
+    } else {
+        qDebug("XXXXXX %s bitSize %d max %llx",
+                qPrintable(field->currentText()),
+                fieldAttrib.bitSize, fieldAttrib.max);
 
-    findValue->setType(FieldEdit::kUInt64);
-    findValue->setRange(0, fieldAttrib.max);
+        findValue->setType(FieldEdit::kUInt64);
+        findValue->setRange(0, fieldAttrib.max);
 
-    replaceValue->setType(FieldEdit::kUInt64);
-    replaceValue->setRange(0, fieldAttrib.max);
+        replaceValue->setType(FieldEdit::kUInt64);
+        replaceValue->setRange(0, fieldAttrib.max);
+    }
 }
 
 void FindReplaceDialog::on_buttonBox_accepted()
diff --git a/common/macaddressvalidator.h b/common/macaddressvalidator.h
index bc04be8..6c5d806 100644
--- a/common/macaddressvalidator.h
+++ b/common/macaddressvalidator.h
@@ -20,18 +20,33 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>
 #ifndef _MAC_ADDRESS_VALIDATOR_H
 #define _MAC_ADDRESS_VALIDATOR_H
 
-#include <QRegExpValidator>
+#include <QRegularExpressionValidator>
 
-class MacAddressValidator : public QRegExpValidator
+// Allow : or - as separator
+class MacAddressValidator : public QRegularExpressionValidator
 {
 public:
     MacAddressValidator(QObject *parent = 0)
-        : QRegExpValidator(parent)
+        : QRegularExpressionValidator(
+                QRegularExpression(
+                    "([0-9,a-f,A-F]{2,2}[:-]){5,5}[0-9,a-f,A-F]{2,2}"),
+                    parent)
     {
-        // Allow : or - as separator
-        setRegExp(QRegExp("([0-9,a-f,A-F]{2,2}[:-]){5,5}[0-9,a-f,A-F]{2,2}"));
     }
-    ~MacAddressValidator() {}
+
+    virtual void fixup(QString &input) const
+    {
+        QStringList bytes = input.split(QRegularExpression("[:-]"),
+                                         QString::SkipEmptyParts);
+
+        if (!bytes.isEmpty() && bytes.constLast().size() == 1)
+            bytes.last().prepend("0");
+
+        while (bytes.count() < 6)
+            bytes.append("00");
+
+        input = bytes.join(":");
+    }
 };
 
 #endif